• Journal of Life Science
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• v.6 no.1
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• pp.34-39
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• 1996

The biopolymer membrane could be formed using marine polysaccharides. Chiotsan and alginate were used for the formation of capsule membrane to mimic the fish eggs such as flying fish eggs and salmon eggs. The size of capsules ranging 1 to 5mm was prepared and the mechanical tests were performed to determine the mechanical similarities to natural fish eggs. The similar mechanical pattern between the synthetic capsules and natural eggs could be found. The controlling parameters for the strength of capsules were pH of the chitosan solution. This encapsulation technique can be broadly applied to medical, engineering as well as food areas.

• Korean Journal of Fisheries and Aquatic Sciences
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• v.36 no.5
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• pp.486-494
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• 2003

Distribution of ichthyoplanktons and its relation to environmental factors (temperature, salinity, $chlorophyll\;\alpha$) around the Youngsan River Estuary of Mokpo, southwest coast of Korea were investigated based on the samples collected bimonthly from February to December, 2001. Unidentified fish eggs were most abundant $1,345\;eggs/100m^3$ in August, while eggs of Engraulis japonicus were most abundant $63\;eggs/100m^3$ in June. A total of forty species of fish larvae and juveniles belonging to the twenty families under six orders were caught, with six gobiids, four icefishes, four croakers and three herrings being represented. Fish larvae and juveniles peaked $17,757\;inds./100m^3$ in August, which consisted of $91.02\%$ of gobiids, $3.69\%$ of gunnels and $3.67\%$ of icefishes, and they were most abundant $7,467\;Inds./100m^3$ at St. 7. Cluster analysis based on the individuals of fish larvae and juveniles showed that six months were classified into two groups at the dissimilarity 70, the first was composed of June and August and the second was February and December and April and October were not clustered with any other months. In August when species diversity index was the highest, eight stations were classified into two groups at the dissimilarity 70, the first was composed of St. 1, 3, 4, 5 and 8 and the second was St. 6, 7 and 2. As a result from correspondence analysis, there is no effect of the environmental factors with a density of fish eggs and larvae, but correlation could be found between a density of fish eggs and $chlorophyll\;\alpha.$

• Korean Journal of Fisheries and Aquatic Sciences
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• v.44 no.1
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• pp.8-17
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• 2011

To identify and examine the distribution of proteolytic inhibitory activity in crude extracts from fish eggs, and to determine the applicability of these protease inhibitors as anti-degradation agents in surimi-based products and fish meat, we compared the inhibitory activities of various extracts from fish eggs to those of commercial proteases, such as trypsin and papain. We used the optimal conditions for the screening of trypsin activity: 30 ug/uL of 0.1% trypsin and 0.6 mM Na-benzoyl-L-arginine-p-nitroanilide (BAPNA) with a pH of 8.0 at $40^{\circ}C$ for 60 min. The activities of papain and four commercial proteases were investigated after mixing with 100 ug/uL enzymes and 0.3% casein with a pH of 8.0 at $40^{\circ}C$ for 60 min. We performed a screening assay to detect the inhibitory activity (%) of crude extracts from eight species of fish eggs against the target proteases trypsin and papain. The assay revealed a wide distribution of trypsin and papain inhibitors in fish eggs. The specific inhibitory activities (11.6.28.6 U/mg) of crude extracts from fish eggs against trypsin and BAPNA substrate were higher than that (0.64 U/mg) of egg whites, used as a commercial inhibitor. The inhibitory activities of crude extracts from fish eggs against trypsin, and of egg whites against casein substrate (1.94.4.51 U/mg), were higher than those of papain (0.24.1.57 U/mg) and commercial protease (0.04.0.32 U/mg). The extracts from fish eggs were rich in protease inhibitors that exhibited strong inhibitory activity against trypsin, a serine protease, and papain, a cysteine protease.

• Korean Journal of Fisheries and Aquatic Sciences
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• v.51 no.1
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• pp.72-78
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• 2018

Fish eggs and larvae were collected in July and November of 2013 and January and May of 2014 to determine seasonal variation in the species composition of ichtyoplankton. Samples were classified based on morphological characteristics. Fish eggs were identified as belonging to five taxa; the most dominant species of fish eggs was Engraulis japonicus (62.05%) followed by Sardinops melanostictus (21.02%) and Leiognathus nuchalis (13.71%). These three species accounted for 96.8% of the total number of fish eggs collected. Larvae of 17 species in six families, and six orders were collected. The most dominant species of fish larvae was E. japonicus (51.79%), followed by L. nuchalis (12.59%) and Omobranchus elegans (12.08%). These three species accounted for 76.46% of the total number of larvae collected. Jinhae Bay was identified as a major spawning and nursery ground for fish species inhabiting in the south coast of Korea, such as E. japonicus, L. nuchalis, S. melanostictus, and Omobranchus elegans. Therefore, management of marine fish resources in the South Sea should necessarily include the ecological management of Jinhae Bay.

• Korean Journal of Fisheries and Aquatic Sciences
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• v.50 no.6
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• pp.829-836
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• 2017

This study investigated the species composition and abundance of floating fish eggs to determine the timing and location of spawning of fish inhabiting the coastal waters of Sagye, Jejudo Island. Eggs were collected with a Bongo net bimonthly from May 2009 to February 2010. Identifications were based on nucleotide sequences of the mitochondrial cytochrome c oxidase subunit I (COI) gene. Eggs were determined to belong to 43 distinct taxa, 35 of which were identified to the species level. The assemblage spanned eight orders, 23 families, and 32 genera. The number of taxa collected varied from month to month, with 14 taxa (12 species) found in June 2009, 11 taxa (10 species) in October 2009, 10 taxa (nine species) each in August 2009 and February 2010, eight taxa (six species) in April 2009, and five taxa (four species) in December 2009. Five abundant species (Branchiostegus japonicus, Engraulis japonicus, Pseudolabrus sieboldi, Goniistius zonatus, and Halichoeres tenuispinis) together represented 52.8% of the total number of eggs collected during the study.

• Ocean and Polar Research
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• v.24 no.4
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• pp.443-448
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• 2002

A study on the ichthyoplankton assemblage was conducted around Dokdo in the East Sea in September 1999 and May 2000. Sixteen species of fish larvae including eggs were collected during the surveys. Anchovy (Engraulis japonicus) eggs and larvae were comprised of 2.0% and 94.5% of total samples in number, respectively. Muller's pearlside (Maurolicus muelleri) eggs and larvae were comprised of 95.0% and 3.2%, respectively. The other species mostly composed of warm water species were less than 2% of total samples in number. The number of species and abundance of the fish lawae and eggs were higher in September than in May. Although there were limited data on the ichthyoplankton around Dokdo in summer and winter, this study area seems to be used for the spawning or nursery ground of fishes.

• Applied Microscopy
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• v.26 no.3
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• pp.277-291
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• 1996

The structures of the egg envelope in fertilized eggs of three species of characidae, head and tail light fish (Hemigrammus ocellifer), black tetra (Gymnocorymbus ternetzi), and buenos aires tetra (Hemigrammus caudovittatus) were studied using light and electron microscopes. The fertilized eggs in all species were colorless, transparent, spherical and non-floted type. The egg envelopes have a single micropyle resembling the pathway of sperm in the area of the animal pole. The micropyle was surrounded by protruded lines of the egg envelope in a radiated form. Egg envelopes of fertilized eggs in both head and tail light fish and buenos aires tetra consisted of three distinct layers; an outer layer, a middle layer and an inner layer. And that of blacktetra consisted of two layers; an outer layer and an inner layer. Also, an outer layers of both head and tail light fish and black tetra were adhesive types but, in that of buenous aires tetra was non-adhesive type. An outer surface of egg envelope in black tetra was arranged by pores regularly. In that of head and tail light fish and buenos aires tetra have a rough side. An inner layer of egg envelope in fertilized eggs consisted of lamellae alternating with interlamellae of lower electron density; an inner layer of fertilized eggs in head and tail light fish consisted of three layers, that of black tetra was four layers, and that of buenos aires tetra was five layers.

• Korean Journal of Fisheries and Aquatic Sciences
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• v.55 no.2
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• pp.146-153
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• 2022

The vertical distribution and abundance of icthyoplankton in the southern waters of Jeju Island during June 2020 were investigated. Fish eggs and larvae were identified using the mitochondrial DNA cytochrome c oxidase subunit I (mtDNA COI) and the 16S rRNA gene. During this period, fish eggs of 23 taxa belonging to 21 families and larvae of 27 taxa belonging to 25 families were collected. Fish eggs were located mostly from the surface to 30 m depth of the water column. Larvae were located from the surface to 80 m depth of the water column. Vertical distributions of fish eggs and larvae were influenced by oceanography conditions such as temperature, salinity, and thermocline depth. No discernible difference in mean thermocline depth was observed between day and night.

• Journal of Aquaculture
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• v.12 no.1
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• pp.31-38
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• 1999

The dietary value and fatty acids composition for the hatched neonates from the resting eggs of marine roofers, Brachionus plicatilis and B. rotundiformis were compared with that for mass-cultured rotifers (control) by feeding them to larvae of flounder (Paralichthy olivaceus) and parrot fish (Oplegnathus fasciatus). Resting eggs were mass-produced in $1~4m^3$tanks by feeding Chlorella sp. and baker's yeast. The B. plicatilis and B. rotundiformis eggs were preserved at $5^{\circ}C$ in darkness for 3 and 5 months, respectively, and hatched at $28^{\circ}C$ under continuous light. The hatched neonates from the resting eggs and mass-cultured rotifer, which was used as a rontrol were fed to fish larvaes. The growth and survival rates of parrot fish larvae fed on the neonates from the resting eggs of B. rotundiformis were similar to those of fish larvae fed on the control rotifer. And the growth and survival rates of the flounder larvae with neonates from the resting eggs of B. plicatilis were similar or higher than those fed the control rotifer. Also the fatty acids composition of the neonates from the resting eggs of B. plicatilis and B. rotundiformis were similar to those from the control rotifers. This results showed that the hatched neonates from resting eggs of rotifer could be used as an effective diet for flounder and parrot fish larvae.

• Fisheries and Aquatic Sciences
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• v.26 no.5
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• pp.318-335
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• 2023

It is important to understand the biological aspects of fish for fishing management. This study was conducted from February through October 2021. A total of 1,629 fishes were collected using different fishing gears. The length-weight relationship is a power curve for all fishes and showed a significant (r² > 0.8). All fishes revealed a negative allometric growth pattern except Labeobarbus intermedius. Oreochromis niloticus (1.714 ± 0.009) was found in better condition than other fish species (analysis of variance [ANOVA], p < 0.05). The length at maturity was 24.0 cm and 25.4 cm total length (TL), 28.9 cm and 28.2 cm fork length, and 53.2 cm and 57.5 cm TL for females and males of O. niloticus, L. intermedius and Clarias gariepinus, respectively. Fecundity was ranged between 100-947 eggs/g with absolute fecundity (AF) of 468-3,832 eggs, 200-1,000 eggs/g with AF of 2,752-136,420 eggs, and 505-900 eggs/g with AF of 2,000-6,404 eggs for O. niloticus, C. gariepinus, and L. intermedius, respectively. Their respective mean fecundity was 1,490 ± 91, 23,330 ± 5,070, and 3,096 ± 273 eggs, respectively. Mean fecundity revealed a significant variation between size classes and species (ANOVA, p < 0.05). The fecundity length and fecundity-body weight relationships except (O. niloticus) of fishes were curvilinear while the gonad weight (GW)-fecundity relationship was linear for all fish species. The fecundity was moderately associated with increasing length than body weight, and GW for all fishes (r² > 0.6). In conclusion, a tangible management setup is required to sustain the use of fish in the reservoir.